Cameron wants 'family-friendly' UK

Support for the family is the key to curing social ills like crime, drug abuse and educational under-performance, cutting the cost of government and paving the way for "sustainably lower taxes", Mr Cameron told the party's Spring Forum in Gateshead.

He repudiated the traditional right-wing focus on the need for a two-parent family, insisting it "doesn't reflect the realities of bringing up a child" in modern Britain and hailing the efforts of "single parents, divorced parents, widows" to raise their children well.

And he took on the arguments of some on the right of the party who believe the Tory leader should base his appeal to voters on an offer of tax cuts instead of concentrating on "soft" issues like the family and the environment.

In a clear signal to activists that he cannot guarantee early tax reductions, he warned: "There is not going to be some magic pot of money waiting for us when the next Conservative government is elected. So we need to get used to saying 'no' more often than 'yes'."

And he added: "I know what some of you might be thinking. All this family-friendly stuff he's going on about: it's not really very Conservative, is it? Let me tell you why I think it's not just Conservative, but it's seriously Conservative.

"If we Conservatives are serious when we say we want a smaller state and lower taxes, we have to have a serious plan for making it happen. And the truth is this: you won't end up with sustainably lower taxes unless you cut the real costs of government. And the real costs of government are the social problems that cause public spending, and the state, to grow and grow."

Cutting the costs of government means reducing crime, drug and alcohol abuse and anti-social behaviour, and ensuring that children leave the education system with the qualifications they need to avoid a life on welfare, he said.

"Of course there are other factors, and all individuals are responsible for their actions," said Mr Cameron.

"But we will never get to the heart of the big problems we face, whether it's crime, anti-social behaviour, welfare dependency or anything else, if we go on pretending that government can pull levers and find the answers. Real, lasting, long-term change means backing parents, backing commitment and helping the best institution in our country - the family - to do the vital work it does."